In the field of perinatal medicine there are a large number of diseases in which controlled respiration is required due to the lack or insufficiency of breathing. In a significant parts of cases requiring such respiration the problem is caused by some kinds of pulmonary malfunction, however, certain other types of diseases (e.g. paralysis of the breathing center,) also require controlled respiration. Of the respiratory problems of new-born and premature infants the idiopathical distress syndrome has a high incidence and it forms a major factor in perinatal mortality.
The controlled respiration raises in perinatal medicine a number of special demands which are different from normal respiratory practice. For that reason the miniaturization of conventional respiratory devices cannot solve the specific problems of perinatal respiratory diseases. Although there are already a number of respirator devices designed particularly for use in perinatal medicine, everyday practice has shown that they could not solve in general the problems in this particular field and they proved to be useful in comparatively narrow fields of indications only.
The handling of pneumatically controlled respirators designed for perinatal medicine is often inconvenient and such respirators cannot be used for the treatment of a number of respiratory problems. For example, one problem connected with such respirators lies in that the pressure of the expirated gas cannot be adjusted to the required values. According to another problem in the expirating periods, pressures below the atmospheric value might take place i.e., the respiration with continuous positive pressure and the respiration with alternating positive pressure cannot be implemented, although such kinds of respiration are considered to be necessary for the respiratory treatment of new-born infants.
The above summarized problems are also connected with respirators controlled electronically, because in such respirators the possibility of adjusting the pressure of expirated gas below the atmospheric value is also not excluded.
Apart from these main problems conventional respirators do not meet the complex requirements of perinatal respiration when their other facilities like handling capabilities, adjustability and the performance in various breathing modes are considered.
The practice in perinatal respiratorial therapy necessitates that the mode of respiration should be brought in correspondence with the type of the actual respiratory problem. Those kinds of respirator devices are required which can provide for a controlled mechanical respiration with alternating positive pressure if the lack or insufficiency of spontaneous breathing is detected. This can be effected by an atmospheric pressure at the ending phase of the expiration, or by adjusting a slight positive pressure at the end of the expiration. In many respiratory disturbances it is required that the spontaneously breathing new-born or inmate baby breathe from a continuously streaming oxygen-air mixture with positive pressure.